Method for making corrugated stovepipe-elbows.



No. 805,490. PATENTED NOV. 28, 1905. A. G. SGHERER.

METHOD OF MAKING CORRUGATED STOVEPIPE ELBOWS. APPLICATION FILED AUG. 7,1903.

aktoznuf UNITED STATES PATENT OFFICE.

METHOD FOR MAKING CORRUGATED STOVEPlPE-ELBOWS.

Specification of Letters Patent.

Patented Nov. 28, 1905.

Application filed August 7, 1903. Serial No. 168,643.

To all whom it may concern:

Be it known that I, ALBERT G. SCHERER, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illi nois, have invented certain new and useful Improvements in Methods of Making Corrugated Stovepipe-Elbows, of which the following is a specification.

My present invention relates to an improved method for making corrugated stovepipe-elbows; and the main object of my invention is an improved method by means of which a corrugated stovepipe-elbowis formed of a single sheet of metal provided with a centrally-arranged lap-joint and two end locking-joints, then forming the sheet into a tube by lapping the centrally-arranged joint and engaging the lock-j oints of the blank, and then placing the tube so formed in a machine, so as to form circumferential corrugations in the tube bounded by the inner ends of the lock-joints and compress the corrugated portion together at the lap-joint to form the throat of the elbow.

In the accompanying drawings, Figure 1 is a plan view of a sheet-metal blank in its first stage. same formed into a tube looking toward the joints thereof. Fig. 3 is a side elevation of a completed elbow made from said tube. Fig. 4 is an elevation looking toward the throat of said elbow. Fig. 5 is a cross-section showing the lock-joints.

Referring to the drawings and in order to describe my improved method minutely, I use a sheet-metal blank A, and upon the opposite edges B B, I provide the centrallyarranged projecting edges C C, respectively. Upon the portion of their edges which extends in opposite directions from these pro- Fig. 2 is a similar view of the jecting edges I provide the locking-flanges D D, this construction being clearly shown in Fig. 1 of the drawings. In Fig. 2 of the drawings this blank is rolled so as to form a tube E, in which the projecting edges C C are overlapped, and the locking-flanges D D are hooked one Within the other, so as to securely hold the meeting edges of the blank together to form the tube. This tube so formed is now placed in any suitable crimping-machine, whereby circumferential corrugations F are formed upon the tube adjacent to the lap-joint G, formed by the projections C C. The corrugations upon the throat H of the elbow J are compressed together, so as to form a compressed crimping or corrugated portion at the lap-joint which is at the throat of the elbow.

What I claim as new, and desire to secure by Letters Patent, is

A method for producing sheet-metal elbows consisting of providing a sheet of material with oppositely-arranged hooked edges upon opposite sides and ends of the blank, forming the same into a tube so that the central portion between the hooked ends overlaps and projects beyond the hooked ends as the hooked ends are engaged, corrugating the tube between the hooked or locked joints thereof, and compressing the corrugations at the lap-joint upon the inside of the elbow, whereby an absolutely sealed joint is formed between the meeting edges of the section.

In testimony whereof I aflix my signature in presence of two witnesses.

ALBERT e. SCHERER.

Witnesses:

IRVING CRnGo, GEORGE J. DREISKE. 

